Driving arrangements



Apr1l21.,'1959 n D. s. RIDLER r-:rAL 2,883,475'

- DRIVING ARRANGEMENTS Filed July 14. 1954 F/G. 2. n

Inventors D. S. Rl DLE R B. F. RMSBY By @m1 A ttorne y United States Patent y DRIVING ARRANGEMENTS Desmond Sydney Ridler and Bernard Frank Armsby, London, England, assignors to International Standard Electric Corporation, New York, N.Y.

Application July 14, 1954, Serial No. 443,398

Claims priority, application Great Britain August 14, 1953 1 Claim. (Cl. 179-1002) The present invention relates to band driving arrangements, and particularly but not exclusively to magnetic storage device using such driving arrangements.

An object of the invention is to provide a magnetic storage device which is inexpensive to construct and which will carry more information per unit weight than magnetic storage devices heretofore used.

Another object of the invention is to provide a driving arrangement for a magnetic storage device which is simple and requires less accuracy in manufacture.

Still another object of the invention is to provide a pneumatic driving larrangement for driving a thin baud past a stationary object.

According to the present invention there is provided:

A magnetic storage arrangement comprising a member having a surface of magnetizable material, and means for driving said member pasta stationary object, characterised in this, that said driving means comprises means for directing `a liow of gas against a surface of said member in a direction which will produce a component of force in the desired direction of movement of said member whereby said member is driven in the desired direction and maintained spaced from said ow directing means.

According to the present invention there is further provided:

A magnetic storage arrangement comprising a member having a surface of magnetizable material, and means for driving said member pasta lstationary object, characterised in this that said driving means comprises means for producing a plurality of jets of 'a gas and for directing each of said jets against a surface of said member in a direction which will produce a component of force in the desired direction of movement of said member, whereby said member is driven in the desired direction and maintained spaced from said jet producing land directing means.

According to the present invention there is still further provided:

A band driving arrangement comprising la reservoir adapted to contain gas under pressure, and means adapted to guide a band in close proximity to 'a surface of said reservoir, said surface of said reservoir having at least one duct leading from the interior through which the gas is forced in such a direction as to maintain said band spaced from said lsurface and create a component of force in the plane of said band which will move said band past said surface.

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of several embodiments of the invention taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a cross-sectional View of one embodiment of the invention showing a cylindrical magnetic drum formed by a thin endless band;

Fig. 2 is a side view of the driving arrangement of the drum of Fig. 1;

Fig. 3 is a pneumatic driving arrangement for mag- Mice 2 netic tape, .e. for a band which might well be nonendless.

Fig. 4 is an alternative form of magnetic recording medium with pneumatic drive.

Figs. 1 and 2 show a simple magnetic drum embodying the invention. The recording medium is a cylinder 1, formed by 'a exible band of plastic which carries a film of magnetic material. The edges of this plastic band are preferably fastened together in Ian edge-on manner analogous to butt-welding. This band is fitted 'around a hollow cylinder 2 of some suitable metal, such as brass, which is drilled with holes, such as 3 and 4, at an angle to the radii of the cylinder in a plane perpendicular to the axis thereof.

The cylinder 2 is mounted rigidly between two end plates 5 and 6, one of which can be removed readily, for example by undoing one or more bolts or nuts. Compressed air is fed to the inside of the cylinder 2 by 1a pipe 7, 'and this air leaves the cylinder 2 by the holes, such .as 3 and 4.

There are therefore produced a large number of jets of air which are directed obliquely on the inner surface of the cylinder 1 which forms the recording medium, and these jets drive the cylinder 1. The cylinder 2 forms a reservoir for the driving air, which tends to smooth out slight irregularities in the air ow. When the supply is switched on, cylinder 1 rotates smoothly at a constant speed.

The usual recording heads are mounted in close proximity to the recording surface. A preferred arrangement is for each head to be lightly spring-biased towards the recording surface, and to be held away from the surface by a jet of compressed air mounted on the head and directed against the recording surface. Adjustment of the pressure of this jet is effected until the required headrecording medium clearance is obtained. Clearly, of cours-e, other methods of mounting the heads can be adopted.

The space between head and drum must be maintained as small and 'as constant as possible in order to obtain a high density of information on the surface and a constant output. The head must never touch the drum, lest it damage itself or the surface. The necessity for maintaining this constant clearancc by normal engineering methods drives the designer to use large bearings and high density stress-free materials, the result being that the drum is not only expensive to manufacture but also very heavy and large in relation to the quantity of storage medium involved. For example, a medium-sized drum weighs about 11/2 hundredweight and uses a few ounces of magnetic coating.

The following application of the invention to a mag netic drum shown in Figs. l 'and 2 offers these advantages over the conventional drum.

(a) It will have a higher information/weight and information/ volume ratio. A

(b) It will reduce dilicult machining.

(c) It will be cheaper.

Fig. 3 shows the application of the pneumatic drive principle t-o a magnetic tape 10. This tape passes between a reservoir 11 and two reservoirs 12 and 13. Holes, acting as ducts, such as 14, 15 and 16, slanted in the desired drive direction are provided.

With the compressed air feed, the air, of course leaves the reservoirs in the direction indicated 'by the larrows, so that the tape is driven from right to left. The tape may be stopped by changing the air liow from compression to suction in either the lower reservoir 11 or the upper reservoirs 12 and 13. These latter could therefore be parts of a single reservoir. The head is mounted in the space 17 between reservoirs 12 and 13.

um. A number of heads such as that indicated dia- `gramrn'atically at 23 are provided adjacent to the band 22. At this point the band preferably passes over a fixed solid surface, not shown. As indicated by the pipe 24, the heads each have an air jet provided, 'and they are lightly tensioned against the band 22, the jets setting the head band clearances.

Returning now to the cylinders 20 and 21, which are si-milar in construction to the cylinder 2, Figs. l and 2, it will be vseen that they differ from the cylinder 2 in that the holes forming the jets are not arranged all round their surfaces. Instead they are arranged only where the band 22 touches the cylinders. The feeding arrangements for the compressed air are not shown in Fig. 4 since they "are the same as those for Figs. 1 and 2.

Although compressed air has been used in the arrangements described, any other suitable gas may be used instead.

While we have described labove the principles of our invention in connection With 'specific apparatus, it is to be clearly understood that this description is made only by way of example and not as 'a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claim.

What We claim is: 1

A magnetic storage arrangement comprising a stationary cylindrical reservoir adapted to be lled with gas under pressure and provided with a plurality of small holes substantially equidistantly spaced around the circumference thereof and extending through the wall of the reservoir 'at substantially the same angle with respect to radii of said reservoir for producing jets 'as the gas is forced through them under pressure, a thin band of lightweight material having a magnetizable surface around said reservoir, said band being formed int-o an endless loop slightly longer than the circumference of said reservoir so as to lit loosely therearound, whereby said band is driven around said reservoir in the direction of s'aid jets and is maintained out-of-contact with said reservoir by the gas, and means for limiting laxial movement of said band with respect to said reservoir.

References Cited in the tile of this patent UNITED STATES PATENTS 1,161,346 Schmidt NOV. 23, 1915 2,037,806 Little Apr. 21, 1936 2,043,788 Adair June 9, 1936 2,253,005 Wittich Aug. 19, 1941 2,542,506 Gibson Feb, 20, 1951 2,612,566 Anderson Sept. 30, 1952 

